Integumentary Systems If an animal in the wild is exposed to ultraviolet (UV) rays, how do they protect themselves from UV exposure?

Integument and UV Rays

Integumentary System A external system that protects the internal organs and structures of animals

The Importance of the Integument Protection from Abrasion Puncture Invasive bacteria desiccation water saturation UV rays

Key organ of the human integumentary system: The skin; made up of: epidermis: a single- layered outermost tissue dermis- the inner layer that contains follicles, sweat glands, muscles, nerves, and blood vessels

The integumentary system may also provide additional protection in the form of: Exoskeleton (found in arthropods) Hair or fur Feathers Scales (in reptiles and fish) Pigments Structural Coloration

Exoskeleton Found in arthropods such as insects and crustaceans A two-layered complex cuticle A non-cellular material secreted by the epidermis

Hair or fur Found in mammals Originates from the epidermis A thread-like protein composed of keratin Found in a range of earth-tone colors (brown, black, red, or yellow)

Feathers Found in birds Originates from the epidermis A highly branched structure composed of keratin One of the most complex integumentary systems in the biological world

Scales Found in reptiles, fish, butterflies and moths wings, the feet of birds Originates from the epidermis Small rigid plates of protein composed of keratin Found in a range of sizes and colors

Pigment Large molecules that reflect light The most common melanin is a group of black or brown colors Melanin can range from yellow and to red in color Produced by special cells in the epidermis

Structural Coloration Found in butterflies, certain beetles, and a few fish They can reflect light They give off iridescent and metallic hues Found in the cuticle or scale Composed of several stacks of plate-like structures

Why is UV protection important? Sunlight plays a key role in synthesizing vitamin D in the human body; however, overexposure to UV rays over time can: Age the skin prematurely Cause the skin to become dry and leathery In high doses, it can cause genetic mutations Cause skin cancer 1 million new cases of skin cancer occur in humans each year